Are they 'Ford-fit' specifications? If so, they should fit. I know that 4x100 PCD will fit with wobbly bolts (Punto is 98mm PCD), and that a 15" x 7J will fit, but I am not sure what the ET value is for the Punto.
If they do fit, then 195/50 R15 is the recommended tyre size to retain your outer rolling radius and therefore your speedometer calibration.
No the ET is too far out unless you run big spacers. You want no higher than ET35 as wheels will sit too far in the arch and catch on the shock bolt at anything above ET 35.
To the OP - because no-one really does Fiat-fit aftermarket wheels, I opted to use genuine Fiat wheels from a later Punto to save all the hassle. That way, I know the centre-hub, PCD and offset are guaranteed to tally. The onyl manufacturer I know that does genuine Fiat-fit is OZ.
No wheels are really ever a direct fit to any car. 90% of the time spigots will have to be used to reduce centre bore so that the wheel sits correctly on the hub.